That's a little more than my 35 miles commute. Hmm, then maybe it is MOSTLY the 115 temperatures. At that temp, the IMA may not help at all for quite some time, as it's so hot that USING the IMA battery (or charging it for that matter) could be harmful for it. While (and if) the IMA is not being used, the ICE must provide ALL the power for your AC, too (rather than the potential combination of ICE and IMA AC compressors).
Do you notice any different behavior out of the IMA on the commute home?

 

If you put a thermometer in the air vent you will find that the output temperature is actually colder when the fan is at a lower setting. Also the compressor works less when the fan is at a lower setting because the evaporator stays cooler with less hot air moving thru it. The catch is that it takes longer to cool the entire car, but if you are just looking for "some" cool air blowing on your body, this might help lower your compressor on time.

It's worth a try!
08FEH

 

I concur with gumby's observations. This is just my first summer with the HCH II, but I think I'm developing a few good strategies for dealing with extreme (100+) heat and a car that hasn't been parked in the shade.

1. open all the doors and get all the windows down for a few minutes before driving away. If it's 110-115 outside, it's a lot hotter in the car, and you want the "coolest" air possible, which is outside. (If possible in terms of security, leave the windows down while parked.)

2. open the trunk for a few minutes, to let some of that heat rise out of there. The trunk is an oven, and while the battery gets its cooling from the cabin, it's adjacent to the rear deck, whose metal understructure is probably too hot to even keep your hand on for long in these temps.

3. Don't force auto-stop at lights. You're probably seeing less auto-stopping, because when the AC is at high load (big differential between interior temp and set temp on the climate control) it'll keep the engine running to use all the compressor instead of just the electric half. But FAS-ing only ensures the car stays hotter longer, and that ensures the batteries are staying hot and thus not as available for boost. Bite the bullet for a few stoplights.

4. Consider preventing autostop altogether until climate control set to auto at 85 no longer runs the fan on high. With mine, pretty quickly it's *willing* to AS, but I've noticed that when I let it, in stop-and-go driving, the battery just goes down-down-down and stays there and then it won't auto-stop but it won't charge up either.

5. Accelerate slower if/when possible. With the AC compressor fully engaged, there's a lot of drag on the engine, and to get normal acceleration you need either a lot of IMA (and resultant regen) or getting over the 3,000 RPM mark, both of which will compound the mileage loss. If you can afford to, keep the low revs for acceleration and just accept the pokiness.

6. It seems to cool better in sustained highway running than in stop-and-go. The AC runs cooler when the engine isn't idling.

A lot of that is just to say, try to let the car do just one thing at a time to the extent possible: first cool down, then save gas. In extreme conditions, it won't do both at the same time. But I find that in 100-105 degrees, setting it to auto-80 degrees and letting it get down, once it has my mileage goes up to nearly (within 2-3 mpg) normal. (On my commute route, 47-48 mpg instead of 50.)

What other tips do folks have that might help us hotheads do the best we can?

--doug

 

It won't ever auto stop at all, it does not seem to use the IMA much, and sometimes when I take off from a stop i have to step on the pedal more than normal to get it to go.

 

I just got my HCHII last week, and today was the first day that I turned off the A/C (only 77 this Texas morning). My driving experience with/out A/C was night and day. The acceleration was much better, I could E/V glide more often and at longer times with more Assist. Perhaps such a big change is due to it being in the "break-in" period, though.

But now that I've seen what this car can do with the A/C off, hypermiling seems much more attainable.

 

Has there ever been a study (formal or at least "rigorously" informal) on the best strategy for cooling off a car parked in the sun on a hot summer day? I bet that not only hybrids drivers would benefit from this knowledge and save gas, etc.

 

Can you attach a patio umbrella to your car somehow?

 

Geez - seems like a lot of work arounds...

Instead of baking yourself, why not just use the AC at least a little? Your FE will still be better than any other car out there that also has its AC on.

 

The manual suggests that you roll down your windows slightly while moving and have the A/C on. I suppose that the hot air goes out the windows, and the car cools down a bit quicker.

 

And then there's the obvious--make sure you use a window screen always, and consider tinting the side/rear windows. I've never owned a tinted car, but then again, I've never owned a car with a greenhouse like the '06+ HC...